Cutter chain for mining machines



Oct. 17, 1933. N. K. BOWMAN CUTTER CHAIN FOR MINING MAGHINES Filed June 10, 1932 2 Sheets-Sheet 1 Oct. 17, 1933. N. K. BOWMAN 1,930,466

CUTTER CHAIN FOR MINING MACHINES Filed June 10, 1932 2 Sheets-Sheet. 2

11 16 16 7 7/ "1 PW] [Illllllllll II I I Q 'I Patented Oct. 17, 1933 UNITED STATES PATENT OFFl CUTTER CHAIN FOR MINING MACHINES 12 Claims.

In the mining of coal, it is now the general practice to employ mining machines which embody an endless cutter chain operating in a horizontal or substantially horizontal plane to cut a cleft into the wall or bank of coal and the shelf thereby formed is subsequently broken down by the use of explosives or other means. The cutter chains, as now generally constructed, require the formation of a rather wide cleft or kerf in order to admit the chain and the cutter bar into the kerf as the depth of the same increases, and it is one object of the present invention to provide a chain and cutter bar of such construction that, while a cleft of the desired depth may be readily formed, the width or height of the cleft may be substantially reduced. It will be understood that this cleft is formed in the bank or wall of coal and generally results in the coal in which the cleft is cut beingreduced to a powder so that it cannot be used and represents a loss of value. By the use of the present invention, the height or width of the cleft may be reduced at least onethird and, therefore, one-third of the coal now generally lost will be saved.

Mining is conducted according to two systems or plans. According to one plan, the cleft is cut for a distance of from ten to twenty feet and after the first cleft is formed the machine is returned to its initial position and another cleft formed. By the other plan or system, the clefts are cut for a distance of two hundred feet, more or less, and after the cleft is formed the coal is cut back to the initial starting point of the machine. With the present type of machines, it is necessary to reverse the position of all the bits in the cutter chain, which is a time-consuming and laborious operation, and another object of the present invention is to provide a construction of cutter chain and cutter bar which will permit the chain to be quickly drawn from the cutter bar and then reversed without disturbing the original position of the bits so that the reversal of the chain is accomplished quickly and easily. The invention is illustrated in the accompanying drawings and will be hereinafter first fully described and then more particularly defined in the appended claims.

In the drawings, Figure 1 is a view, partly in plan and partly in horizontal section, of a cutter bar, cutter chain and driving wheel embodying the present invention,

Fig. 2 is a longitudinal section on the line 2 2 of Fig. 1,

Fig. 3 is a transverse section on the line 33 of Fig. 1,

Fig. 4 is an enlarged detail section on the line 44 of Fig. 1,

Fig. 5 is a detail section on the line 5-5 of Fig. 4,

Fig. 6 is a sectional schematic view giving a comparison between the cutter chain and bar of the present invention and the cutter bar and chain according to the construction now most generally employed.

The cutter bar is shown at 1 and the driving wheel is shown at 2. The cutter bar and chain are now generally constructed as shown at the right in Fig. 6 wherein the numeral 3 indicates a transverse section of a portion of the cutter bar and 4. indicates guides secured to the top and bottom of the bar and projecting beyond the edge thereof so as to engage above and below the bit block 5 which is provided with flanges 6 at its inner end on its upper and lower sides which engage behind the overhanging flanges '7 of the guides 4 and between said flanges and the cutter bar 3. According to present practice, sprocket teeth on the driving wheel at the inner end of the cutter bar engage in links which connect the bit blocks and, of course, the bit block must have an appreciable thickness or vertical dimension in order to retain strength enough to be propelled by the sprocket teeth. It is, therefore, necessary to impart substantial vertical dimension to the base or inner side of the bit block and this vertical dimension must be accommodated by the width of the cutter bar and the guide flanges thereon. According to the present invention, the cutter bar is a single integral cast member of the proper dimensions and on its underside it is chambered, as shown at 8, the chamber tapering both vertically and horizontally toward the inner end of the cutter bar so that the weight of the bar may be reduced without endangering its strength. It will be understood that the cutter bar is supported from the framework of the mining machine and the driving wheel 2 is also supported from the framework of the machine, the wheel being provided with clutch lugs 9 on its upper side adapted to be engaged by similar clutch members on the driving shaft of the machine so that it may be easily driven when operation of the cutter is desired. The bit block 10, according to the present invention, is provided with the guide flanges 11 on its upper and lower sides at its back or base and from its base extends a reduced guide rib or stem 12 which enters a groove or channel 13 formed in the edge of the cutter bar, the rib or stem 12 having its end portions converging inwardly for a short distance and a tooth 14 projecting centrally from the inner edge of the stem, as shown clearly in Fig. 1. The tooth 14 is provided on its upper and lower sides at its extremity with lateral lugs 15 which are adapted to ride in the groove 13 of the cutter bar at the base of the latter, as will be understood upon reference to the drawings. Bushings or wear plates 16 are secured to the top and bottom walls of the groove 13 and are provided with angular flanges 16' which extend across the outer edge of the cutter bar and slightly above and below the same to provide wearing surfaces for the bit blocks, as shown clearly in Fig. 3. The inner portions of the plates 16 he at the outer sides of the stem 12 and tooth 14 in front of and adjacent the lugs 15 while the flanges 16 of the plates are disposed at the rear sides of the flanges 11 and thereby effectually serve to retain the bit blocks in proper relation to the cutter bar. It must be noted that at the outer end of the cutter bar one straight side of the groove 13 is continued through the end of the bar, as shown at 17, forming an outlet tangential to the arcuate intermediate portion 18 of the groove. The groove, of course, does not extend across the inner end of the cutter bar but is so located that the teeth of the successive bit blocks leaving the driving wheel will be alined with the end of the groove so as to pass into the same to be guided and supported by the bar.

The bits, indicated at 19, are secured in the bit blocks at the outer sides of the same and project therefrom at varying angles so that the bits which successively engage the face of the coal bank will cut in different paths and thereby quickly cut the cleft of the desired width or height and the width or height, of course, is somewhat greater than the vertical dimension of the cutter bar in order that proper clearance for the bar as it enters the cleft will be provided. The particular manner of securing the bits is immaterial in the present invention.

The driving wheel 2 is provided with sockets or recesses 20 in its periphery at equi-distant points about the same and between the sockets are straight walled tangential grooves or recesses 21, the sockets receiving the teeth 14 and lugs 15 and the grooves 21 receiving the stems 12 so that the rotation of the wheel will be imparted to the bit blocks and chain and said bit blocks will be properly supported and guided. The side walls of the sockets 20 are preferably provided with open ings 20', as' shown, to permit the discharge of coal dust or other foreign matter which may to collect in said sockets. The bit blocks are provided at their ends with openings receiving pivots which connect them to coupling links 22. Ordinarily the coupling links are connected with the bit blocks by rivets which are intended to be permanently fitted in place. Obviously, therefore, it is difficult to separate the links and the bit blocks when the occasion arises, and a particular advantage of the present invention is the facility with which the chain may be released from the cutter bar. To accomplish this result and obtain this advantage, I form one of the coupling links of similar plates 24 which have the same contour as the coupling links 22 and are so disposed as to overlap the opposed ends of adjacent bit blocks and extend over the pivot openings provided in said blocks. On the opposed faces of the plates 24 are formed studs 25 which are circular in cross section and are adapted to fit in the pivot openings provided in the bit blocks, as shown in Fig. i. The studs each equal in height to one-half the thickness of the bit block at its pivot point so that the studs will meet at the centers of the pivot openings. Between the studs 25 hub members 26 are formed on the opposed faces of the plates 24 to extend between the opposed ends of the bit blocks and one of these hubs may be internally threaded, as shown in Figs. 4 and 5. A clamping screw or bolt 27 is engaged through the smooth bored opening of the one coupling plate 24 and engaged in the threaded bore of the other clamping plate whereby the two plates may be firmly secured together so as to pivotally couple the adjacent bit blocks, as will be understood upon reference to Fig. 4. The smooth bored hub 26 preferably has its bore reamed at its outer side so that the head of the clamping bolt or screw may form a countersunk engagement therewith and the ends of the bolts, consequently, lie flush with the outer surfaces of the coupling plates. In order to guard against accidental release of the coupling bolt, a set bolt 28 is mounted transversely in the upper coupling plate 24 and turned home against the smooth shank of the coupling bolt, as shown clearly in Fig. 5. With this construction, when it is desired to reverse the cutter chain, or for any reason it becomes necessary-to remove the chain from the cutter bar, the chain is fed along the bar until the coupling plates 24 are adjacent the end of the bar and the outlet groove 17. The set bolts 28and the clamping bolt 27 are then withdrawn, whereupon the coupling plates may be simply lifted from the bit bodies and that bit body which is then adjacent the inner end of the outlet groove 17 is grasped and drawn through said outlet groove. The entire chain may thus be drawn from the cutter bar and simply turned over and then, by a reverse manipulation, re-engaged with the cutter bar and theseparated bit blocks again coupled.

The cutter bars, as now generally constructed, have a removable nose or distant end member so that if it becomes necessary to remove the chain, the removable nose is first taken off the cutter bar and the chain may then be disengaged from the bar. With the apparatus of the present invention,- it is not necessary to provide a removable nose for the cutter bar and, therefore, the bar is stronger than the bars now in use.

By referring to Fig. 6, it will be readily seen that with the apparatus of the present inven tion it is not necessary to form such a wide cleft heretofore has been necessary and the cutter the chain may be made lighter than ous bars and chains without any sacrifice of strength and with a gain in efficiency inasmuch as less power will be required to operate besides efiecting a very appreciable saving in the product of the mine, as has been previously a sufficient clearance between the cutter ha" a d walls of the cleft to permit proper functioning of said cutter bar.

having thus described the invention, I claim: 1 a machine, a cutter bar having a.

circumferential guide channel formed therein and opening through the outer edge thereof, a cutter chain mounted for rotation on t e cutter bar nd including pivotally connected links and bit blocks arranged to travel wholly on the outside of the cutter bar, and guide teeth projecting laterally from the bit blocks and extending within and having interfitting engagement with the walls of the guide channel to prevent lateral displacement of the cutter chain whereby the thickness of the cutter bar is reduced and the width of the cleft in the coal out by the bits correspondingly reduced.

2. In a mining machine, a cutter bar having a circumferential guide channel substantially T shaped in cross section, a cutter chain mounted for rotation on the cutter bar and including pivotally connected links and bit blocks arranged to travel on the outside of the cutter bar, and a guide tooth projecting laterally from the center of each bit block and provided with oppositely disposed lateral lugs slidably engaging the walls of the guide channel, the upper and lower faces of the bit blocks being disposed in substantially the same horizontal plane with the upper and lower faces of the cutter bar whereby the thickness of the bit blocks and cutter bar will be uniform.

3. In a mining machine, a cutter bar having a circumferential guide channel formed therein and opening through the outer edge thereof, a cutter chain mounted on the cutter bar and including pivotally connected links and bit blocks bearing against and mounted for travel on the outer edge of the cutter bar, and guide teeth projecting laterally from the bit blocks between the upper and lower faces thereof and extending within and having interfitting engagement with the walls of the guide channel to prevent lateral displacement of the cutter chain, the bit blocks being of substantially the same thickness as the cutter bar whereby the width of the cleft in the coal cut by the bits will be reduced without affecting the clearance between the upper and lower faces of the cutter bar and the adjacent walls of said clef necessary to permit proper functioning of said cutter bar.

4. In a mining machine, a cutter bar having a circumferential guide channel, wear resisting strips disposed within the channel and provided with angular flanges covering the outer edge of the cutter bar, a cutter chain mounted on the cutter bar and including pivotally connected links and bit blocks, lateral flanges on the bit blocks bearing against the angular flanges of the strips, and guide members projecting from the bit blocks between the flanges thereof and extending within and having interfitting engagement with the walls of said guide channel, the upper and lower faces of the cutter chain being disposed in substantially horizontal alinement with the upper and lower faces of the cutter bar, whereby the angle of the bits with respect to the cutter bar will reduce the width of the effective cutting area of the bits and cause the cleft formed in the coal by said bits to be correspondingly reduced in width.

5. In a mining machine, a cutter chain including pivotally connected bit blocks having guide ribs terminating in teeth, and a toothed driving wheel having a circumferential channel adapted to receive the guide ribs and spaced sockets formed in the wall of the channel adapted to receive said teeth.

6. In a mining machine, a cutter chain comprising bit blocks having guide ribs terminating in teeth. and a driving wheel having a circumferential channel adapted to receive the guide ribs, said channel being broken at intervals to form sockets of greater depth than the channel and adapted to receive said teeth.

7. In a mining machine, an endless cutter chain comprising bit blocks provided with centrally located guide ribs terminating in teeth, and a driving wheel having a circumferential channel adapted to receive the guide ribs, said channel being provided with spaced sockets of greater depth and width than the channel and adapted to receive said teeth.

8. In a mining machine, a cutter bar having oppositely disposed guide channels substantially T-shaped in cross section, a toothed driving wheel having a circumferential channel registering with the guide channels and provided with spaced sockets, an endless cutter chain composed of connected links and bit blocks, said bit blocks being provided with ribs fitting in the channel of the driving wheel and terminating in laterally enlarged teeth fitting in the sockets and in the guide channels of the cutter bar.

9. In a mining machine, a cutter bar having oppositely disposed guide channels substantially T-shaped in cross section, and an endless cutter chain composed of pivotally connected links and bit blocks, said bit blocks being provided with teeth having oppositely disposed lateral lugs fit ting in the guide channels, and means for driving the chain.

. 10. In a mining machine, a cutter bar having a solid nose and provided with oppositely disposed guide channels, and wear resisting strips bearing against the upper and lower walls of the channels 11. In a mining machine, a cutter bar having a guide channel in its opposite side edges and extending around the nose of the bar, there being an opening in the nose of the cutter bar and communicating with the guide channel, wear resisting strips bearing against the upper and lower walls of the channel and provided with angular flanges extending over and covering the outer edges and nose of said cutter bar, and a tooth carrying chain operating in the guide channel, there being a eak in the strips at said opening to permit ingress and egress of the teeth on the chain when installing the chain or removing it from the cutter bar.

12. In a mining machine, a cutter bar having a guide channel in its opposite side edges and extending entirely around the nose of the bar, there being an opening in the nose of the cutter bar disposed in longitudinal alinement with the guide channel and communicating therewith, wear resisting strips bearing against the upper and lower walls of the channel, and a toothed cutter chain operating in the guide channel and including a detachable link removable through the opening in the nose of the cutter bar for the purpose of reversing the chain without wrecking the teeth.

NEWTON K. BOWMAN. [L.s.] 

